1. Field of the Invention
This invention relates to vehicle occupant safety during a collision, and more specifically to an anisotropic multi-sectional “customized” or “tunable” multi-sectional energy absorber that absorbs energy imparted by an incident object that impacts the absorber, and a method for configuring the absorber.
2. Background Art
Bumpers provide protection to pedestrians as well as occupants during collisions. Designed to absorb and deliver momentum when a vehicle is in an accident, bumpers are provided with designed components. When assembled, the components form a bumper system that is usually mounted on the front and rear of the vehicle. Often built with “crumple zones”, bumpers traditionally include designs that enable a specific bumper part to flex during collisions.
It is desirable for the bumper system to absorb as much impact energy in as little crush distance as possible, with as little weight as possible, yet be capable of being designed and manufactured under favorable economic conditions.
Generally, one or more energy absorbers are positioned between a vehicle occupant and an incident force. In low speed impacts, the absorber serves to minimize damage to the fascia, lamps, and other components. In high speed impacts, the absorber serves to protect occupants and pedestrians from injury.
Conventionally, an energy absorber can be manufactured at relatively low cost by thermoforming and impact performance can be optimized without expensive tooling modification at heights below about 50 millimeters. However, above this height, the base material thickness required to produce an energy absorber for the appropriate crush resistance is such that it cannot easily and inexpensively be produced using in-line thermoforming equipment. In such circumstances, injection molded absorbers can be produced, perhaps at a lower cost.
A search that preceded the filing of this application revealed the following U.S. references Pat. Nos. 7,073,831; 6,938,936; 6,926,321; 6,923,495; 6,863,322; 6,848,730; 6,749,784; 6,746,061; 6,726,262; 6,669,251; 6,550,850; 6,443,513; 6,406,081; 6,247,745; 6,199,937; 5,150,935; 4,597,601; 4,072,334; US2003/0080573; US2004/0036302; US2004/0094977; US2004/0174025; US2005/0057053; US2005/0230204; US2005/0230205; US2005/0269824; and US2006/0028038.